With the development of consumer electronic products such as mobile phones and electronic compasses and the use of conventional products such as motors and actuators, the need of magnetoresistive sensors has grown. More particularly, three-dimensional magnetoresistive sensors are capable of sensing the variations of the magnetic field components along the x-axis, the y-axis and the z-axis that are perpendicular to one another. An electronic compass uses a three-dimensional magnetoresistive sensor to precisely sense the terrestrial magnetic field.
Current three-dimensional magnetoresistive sensing devices have been well-developed. However, most of the conventional arts use multi-chip or three-dimensional structured magnetoresistive sensing devices to sense the variations of the magnetic field components along the x-axis and y-axis in parallel with the substrate plane and the variation of the magnetic field component along the z-axis perpendicular to the substrate plane.
Multi-chip or three-dimensional structured magnetoresistive sensing devices have more complicated configurations, higher manufacturing cost and down-scaled semiconductor elements, which result in difficulties in packing the multi-chip or three-dimensional structured magnetoresistive sensing devices hence low process yield. Furthermore, since the variations of the magnetic field components along the x-axis, the y-axis and the z-axis are sensed by using a plurality of magnetoresistive sensing units with different sensitivities, the values of the sensed results have to be normalized, which results in more significant inaccuracy and poorer sensing quality.
In view of the above, there is need in providing an advanced magnetic-field sensing method to overcome the problems of the prior arts.